diff --git a/src/runtime/c/pgf/db.cxx b/src/runtime/c/pgf/db.cxx
index 1ea4d5e31..efd2347dd 100644
--- a/src/runtime/c/pgf/db.cxx
+++ b/src/runtime/c/pgf/db.cxx
@@ -1,11 +1,29 @@
 #include <stdlib.h>
 #include <string.h>
+
+#ifndef _WIN32
 #include <sys/mman.h>
 #include <unistd.h>
 #include <fcntl.h>
 #include <errno.h>
 #include <pthread.h>
 
+#else
+
+#include <io.h>
+#include <windows.h>
+
+static
+size_t getpagesize()
+{
+    SYSTEM_INFO si;
+    GetSystemInfo(&si);
+    return si.dwPageSize;
+}
+
+#define ftruncate _chsize
+#endif
+
 #include "data.h"
 #include "ipc.h"
 
diff --git a/src/runtime/c/pgf/pgf.h b/src/runtime/c/pgf/pgf.h
index b4f02aaf7..9bb0c0e06 100644
--- a/src/runtime/c/pgf/pgf.h
+++ b/src/runtime/c/pgf/pgf.h
@@ -118,6 +118,7 @@ typedef struct {
 /* Arbitrary size integers are represented as an array of uintmax_t
  * values. Each value in the array is at most LINT_BASE-1 big.
  * LINT_BASE itself is always 10 ^ LINT_BASE_LOG. */
+#if defined(__WORDSIZE)
 #if __WORDSIZE == 8
 #define LINT_BASE 100
 #define LINT_BASE_LOG 2
@@ -133,6 +134,15 @@ typedef struct {
 #else
 #error "Platforms with the current __WORDSIZE are not supported yet"
 #endif
+#elif defined(_WIN64)
+#define LINT_BASE 10000000000000000000UL
+#define LINT_BASE_LOG 19
+#elif defined(_WIN32)
+#define LINT_BASE 1000000000
+#define LINT_BASE_LOG 9
+#else
+#error "Unsupported platform"
+#endif
 
 /* The PgfUnmarshaller structure tells the runtime how to create
  * abstract syntax expressions and types in the heap of